Engine

ABSTRACT

An engine having at least one displacer cylinder in which a liquid, in particular an ionic liquid, is arranged and which can be connected to a feed passage and a discharge passage for a medium, is disclosed. The liquid is operatively connected to a displacer device. The displacer cylinder is arranged in a cylindrical drum, rotatably mounted about an axis of rotation, at an angle to the axis of rotation of the cylindrical drum. In an embodiment, the displacer cylinder is arranged perpendicularly to the axis of rotation of the cylindrical drum, and the displacer cylinder is designed as a radial bore arranged in the cylindrical drum.

BACKGROUND AND SUMMARY OF THE INVENTION

This application claims the priority of International Application No.PCT/EP2006/007332, filed Jul. 25, 2006, and German Patent Document No.10 2005 036 308.3, filed Aug. 2, 2005, the disclosures of which areexpressly incorporated by reference herein.

The invention relates to an engine having at least one displacercylinder in which a liquid, in particular an ionic liquid, is arrangedand which can be connected to a feed passage and a discharge passage formedium, wherein the liquid is operatively connected to a displacerdevice.

These types of engines are used for example as compressors forcompressing gaseous media. The medium in this case is displaced by meansof the liquid in the displacer cylinder, whereby these types of enginesare designated as non-positive compressors. An ionic liquid can be usedas the liquid. However, it is also possible to use liquids with a lowvapor pressure or liquids with low gas solubility. What these types ofliquids have in common is that they do not dissolve in the medium andcan be separated from the medium without leaving a residue so that thecompressed medium exhibits a high level of purity.

A generic engine embodied as a compressor for gaseous media is knownfrom U.S. Pat. No. 6,652,243 B2. In the case of this non-positivecompressor, the liquid in the displacer cylinders is connected to apump, whereby a control valve is provided to control the supply anddischarge of the liquid, and this valve is controlled as a function ofthe liquid level in the displacer cylinders, which is detected by meansof electronic displacement measuring systems. The displacer cylindersare preferably arranged vertically in order to support the discharge ofliquid from the displacer cylinder via gravity. In the case of this typeof compressor, the liquid column cannot be accelerated beyond thegravitational acceleration so that the cycle speed of the compressor islimited by the gravitational acceleration. These types of compressorsrequire a lot of construction space and have limited displacer output.In addition, the electronic displacement measuring systems result inhigher construction expenditures.

The present invention is based on the objective of making available anengine of the species cited at the outset, which does not require a lotof construction space and has high displacer output.

This objective is attained in accordance with the invention in that thedisplacer cylinder is arranged in a cylindrical drum, rotatably mountedabout an axis of rotation, at an angle to the axis of rotation of thecylindrical drum. According to the invention, the displacer cylinder isthereby embodied in a cylindrical drum rotating around the axis ofrotation, whereby the displacer cylinder and thus the longitudinal axisof the displacer cylinder are at an angle to the axis of rotation of thecylindrical drum. Due to the rotation of the cylindrical drum and thusthe displacer cylinder, a centrifugal force that is a function of thespeed of the cylindrical drum acts on the liquid located in thedisplacer cylinder thereby accelerating the liquid. The accelerations ofthe liquid that can be achieved hereby are greater than thegravitational accelerations so that the liquid column in the case of theinventive engine can be moved at a higher speed as compared with a priorart engine, therefore making it possible to achieve a high cycle speed.This makes it possible to provide high displacer output with a lowrequirement for construction space for the engine. In addition, theinventive engine requires only a low quantity of liquid, in particularionic liquid, thereby resulting in low manufacturing costs for theinventive engine.

Special advantages are yielded, if, according to a preferred embodimentof the invention, the displacer cylinder is arranged perpendicularly tothe axis of rotation of the cylindrical drum. This results in a highcentrifugal force, whereby high displacer output can be made availablewith a low requirement for construction space for the engine.

Simple manufacturing of the displacer cylinder can be achieved, if thedisplacer cylinder according to a preferred embodiment of the inventionis designed as a radial bore in the cylindrical drum.

A valve plate is advantageously provided for controlling the connectionof the displacer cylinder to the feed passage as well as to thedischarge passage. A valve plate can be used in a simple manner tocontrol the connection of the displacer cylinder arranged in therotating cylindrical drum to the feed passage and the discharge passage.

In this case, the cylindrical drum is expediently supported in the axialdirection on the valve plate, which is arranged on a housing. Thisdesign allows axial sealing gaps between the displacer cylinders and thefeed passage as well as the discharge passage to be achieved, which canbe sealed in a simple manner allowing the engine to be operated at highoperating pressures with low leakage losses.

The cylindrical drum is advantageously operatively connected to a driveshaft, whereby a drive or an output of the engine can be formed in asimple manner.

If according to a development of the invention, the displacer cylinderis provided with a cooling device, in particular internal cooling,isothermal compression can be realized with an engine operating as acompressor or isothermal expansion with an engine operating as a drivemotor. This allows low thermal stress and strain on the engine to beachieved as well as a high degree of efficiency of the engine. Coolingfins for example can be arranged in the displacer cylinder as thecooling device.

According to a preferred embodiment of the invention, the displacerdevice is embodied as an axial piston machine, whereby each displacercylinder is connected to a cylinder space of the axial piston machine.An axial piston machine that has a rotating cylinder block, in which thecylinder spaces are embodied, allows, in connection with the cylindricaldrum featuring the displacer cylinder, a simple structure and a lowrequirement for construction space for the engine to be realized.

A development of the invention provides that the axial piston machine beembodied as a diagonal plate machine with a diagonal plate, inparticular an adjustable diagonal plate. A diagonal plate machine, whoseconveyance volume and/or absorption capacity can be adjusted, allows thedisplacer output of the engine and the speed of the cylindrical drumthat is provided with the displacer cylinders to be modified in a simplemanner by pivoting the diagonal plate. As a result, it is possible toguarantee in a simple manner that the acceleration of the liquid column,which is caused by the rotation of the displacer cylinder and thus bythe centrifugal forces, is greater than the sinusoidal acceleration ofthe liquid column generated by the axial piston machine, and thereforethat the engine is in equilibrium.

According to a preferred embodiment of the invention, in which the axialpiston machine has a cylinder block equipped with the cylinder spaces,the cylinder block of the axial piston machine is coupled in arotationally synchronous manner to the cylindrical drum accommodatingthe displacer cylinder. This permits a secure and rotationallysynchronous connection to be achieved in a simple manner between thecylinder spaces arranged in the cylinder block of the axial pistonmachine and the displacer cylinders of the cylindrical drum.

If, according to another embodiment of the invention, the cylinder blockof the axial piston machine and the cylindrical drum accommodating thedisplacer cylinder are embodied as a common cylindrical drum, thedisplacer cylinder can be integrated into the cylinder block of theaxial piston machine, thereby making an engine available that has alower number of parts, does not require a lot of construction space andtherefore has low manufacturing expenditures.

With respect to a simple structure and a low requirement forconstruction space, it is favorable, if, according to a development ofthe invention, the cylindrical drum and the displacer device arearranged in a common housing.

According to an advantageous embodiment, the inventive engine can beembodied as a compressor for compressing a gaseous medium, in particularhydrogen. With an inventive non-positive compressor, in which the mediumis compressed by the axial piston machine operated as a pump through theliquid conveyed by the axial piston machine, high compressor output canbe achieved with a low requirement for construction space as well as lowmanufacturing expenditures and a high level of purity of the compressedmedium.

The inventive engine can also be embodied as a drive motor for tappingtorque. Propulsion takes place in this case via the medium, wherebytorque is generated by means of the axial piston machine operated as amotor and driven by the liquid, which can be tapped via the cylindricaldrum and the drive shaft. Due to the inventive radial arrangement of thedisplacer cylinders, high displacer output can be generated in this casewith a low requirement for construction space.

Additional advantages and details of the invention are explained ingreater detail on the basis of the exemplary embodiment depictedschematically in the FIGURE.

BRIEF DESCRIPTION OF THE DRAWING

The FIGURE provides a longitudinal section view of an embodiment of anengine in accordance with the principles of the present invention.

DETAILED DESCRIPTION OF THE DRAWING

The FIGURE depicts a longitudinal section of an inventive engine 1. Adrive shaft 3 is rotatably mounted within a housing 2 around an axis ofrotation 4. A cylindrical drum 5, in which several displacer cylinders 6are embodied, is coupled to the drive shaft 3 in a rotationallysynchronous manner. The displacer cylinders 6 in this case are embodiedas radial bores 14 arranged in the cylindrical drum 5 and are arrangedin a star-shape around the axis of rotation 4, whereby the longitudinalaxis 7 of the displacer cylinders 6 is arranged perpendicularly to theaxis of rotation 4 of the drive shaft 3 and thus of the cylindrical drum5.

In the radial inner region, the displacer cylinders 6 are each connectedto a connecting passage 8, which is operatively connected to aplate-shaped valve plate 9, whereby the connection of the displacercylinders 6 to a feed passage 10 as well as to a discharge passage 11can be controlled by means of the valve plate 9. The cylindrical drum 5in this case is supported in the axial direction on the valve plate 9,which is arranged on a housing cover 12 fastened to the housing 2.

A liquid 15, in particular an ionic liquid, is arranged in the displacercylinders 6.

Each displacer cylinder 6 is connected by means of a connecting passage13 to a cylinder space 16 of a hydraulic displacer device 17 embodied asan axial piston machine having a diagonal plate design. In this case,the displacer device 17 embodied as an axial piston machine has acylinder block 18, which is arranged coaxially to the cylindrical drum 5and is connected to the cylindrical drum 5 and/or the drive shaft 3 in arotationally fixed manner. It is also possible to embody the cylinderblock 18 and the cylindrical drum 5 as a common and therefore one-piececylindrical drum.

The cylinder spaces 16 of the axial piston machine are formed by thelongitudinal bores 20 arranged concentrically in the cylinder block 18,in which bores pistons 21 are respectively arranged in a longitudinallydisplaceable manner. The pistons 21 are each supported on a diagonalplate 23 by means of a sliding block 22. A spherical sliding blockarticulation is embodied between the piston 21 and sliding block 22.

The axial piston machine is embodied as an axial piston machine whosedisplacer volume can be adjusted, whereby the diagonal plate 23 isswivel-mounted on the housing 2 and can be inclined with respect theaxis of rotation 4 by means of a regulating device (not shown). However,it is also possible to embody the axial piston machine with a fixeddisplacer volume, whereby the diagonal plate can be embodied directly onthe housing 2.

In this case, the cylindrical drum 5 and the displacer device 17 arearranged in the common housing.

In the case of an embodiment of the inventive engine 1 as a compressor,the cylindrical drum 5 and the cylinder block 18 are driven via thedrive shaft 3. In this case, the axial piston machine functions as apump and conveys liquid 15 from the cylinder spaces 16 to the displacercylinder 6, whereby the medium flowing into the displacer cylinder 6 viathe feed passage 10 is compressed by the liquid 15 and conveyed to thedischarge passage 11. When the engine 1 is in operation, centrifugalforce acts on the liquid 15 due to the radial arrangement of thedisplacer cylinders 6 through the rotation of the cylindrical drum 5,and this centrifugal force accelerates the liquid, allowing the liquidcolumn to be moved at a great speed and thus the engine 1 can beoperated at a great speed and therefore at a high cycle speed.

Therefore, the construction space of the inventive engine can be reducedas compared to generic compressors having the same conveying capacity,whereby a high conveying capacity with high efficiency can be achievedwith a low requirement for construction space.

Direct control of the conveying capacity is possible due to theadjustable diagonal plate 23 of the axial piston pump. Controlling theconnection of the rotating displacer cylinder 6 to the feed passage 10as well as to the discharge passage 11 via the valve plate 9 makes itpossible to dispense with an electric displacement measuring system,which results in lower manufacturing costs for the inventive engine 1.

In the case of an embodiment of the inventive engine 1 as a drive motor,pressurized medium is supplied to the displacer cylinders 6 via the feedpassage 10. The liquid 15 acts on the pistons 21, whereby the axialpiston machine is operated as a motor and a rotational movement of thecylindrical drum 5 and of the cylinder block 18 is generated, wherebytorque can be tapped on the drive shaft 3.

1-14. (canceled)
 15. An engine having a displacer cylinder in which aliquid, in particular an ionic liquid, is arranged and which isconnectable to a feed passage and a discharge passage for a medium,wherein the liquid is operatively connected to a displacer device,wherein the displacer cylinder is arranged in a cylindrical drum that isrotatably mounted about an axis of rotation, and wherein the displacercylinder is arranged in the cylindrical drum at an angle to the axis ofrotation of the cylindrical drum.
 16. The engine according to claim 15,wherein the displacer cylinder is arranged perpendicularly to the axisof rotation of the cylindrical drum.
 17. The engine according to claim15, wherein the displacer cylinder is designed as a radial bore arrangedin the cylindrical drum.
 18. The engine according to claim 15, wherein avalve plate is provided to control a connection of the displacercylinder to the feed passage and the discharge passage.
 19. The engineaccording to claim 18, wherein the cylindrical drum is supported in anaxial direction on the valve plate, which is arranged on a housing. 20.The engine according to claim 15, wherein the cylindrical drum isoperatively connected to a drive shaft.
 21. The engine according toclaim 15, wherein the displacer cylinder is provided with a coolingdevice.
 22. The engine according to claim 15, wherein the displacerdevice is embodied as an axial piston machine, wherein the displacercylinder is connected to a cylinder space of the axial piston machine.23. The engine according to claim 22, wherein the axial piston machineis embodied as a diagonal plate machine with an adjustable diagonalplate.
 24. The engine according to claim 22, wherein the axial pistonmachine has a cylinder block equipped with the cylinder space, whereinthe cylinder block of the axial piston machine is coupled in arotationally synchronous manner to the cylindrical drum accommodatingthe displacer cylinder.
 25. The engine according to claim 22, wherein acylinder block of the axial piston machine and the cylindrical drumaccommodating the displacer cylinder are embodied as a commoncylindrical drum.
 26. The engine according to claim 15, wherein thecylindrical drum and the displacer device are arranged in a commonhousing.
 27. The engine according to claim 15, wherein the engine isembodied as a compressor for compressing a gaseous medium
 28. The engineaccording to claim 27, wherein the gaseous medium is hydrogen.
 29. Theengine according to claim 15, wherein the engine is embodied as a drivemotor for tapping torque.
 30. An engine, comprising: a displacer device;and a rotatable drum coupled to the displacer device; wherein therotatable drum defines a displacer cylinder and wherein the displacercylinder is arranged in the cylindrical drum at an angle to an axis ofrotation of the cylindrical drum.
 31. The engine according to claim 30,wherein a longitudinal axis of the displacer cylinder is perpendicularto the axis of rotation of the cylindrical drum.
 32. The engineaccording to claim 30, wherein an ionic liquid is disposed within thedisplacer cylinder and wherein a pressure of the ionic liquid isincreased by a centrifugal force imparted to the ionic liquid by arotation of the cylindrical drum.
 33. The engine according to claim 32,wherein the ionic liquid with an increased pressure compresses a mediumsupplied to the displacer cylinder.
 34. The engine according to claim30, wherein the cylindrical drum is coupled to a drive shaft.